Replaceable staple cartridge with retractable knife

ABSTRACT

A surgical stapling device includes a tool assembly having a drive assembly, an anvil, and a cartridge assembly. The cartridge assembly includes a replaceable staple cartridge that includes an actuation sled assembly having an actuation sled, a knife bar, and a retractor link. The retractor link is secured to the knife bar such that the actuation sled assembly is movable through a cartridge body of the staple cartridge. The retractor link is movable from a non-deformed condition disengaged from the drive assembly to a deformed condition engaged with the drive assembly to facilitate retraction of the actuation sled assembly after the stapling device is fired.

FIELD

This disclosure is generally related to surgical stapling devices, andmore particularly, to surgical stapling devices having replaceablestaple cartridges including retractable knives.

BACKGROUND

Surgical stapling devices configured for endoscopic use are well knownand commonly used during surgical procedures to minimize patient traumaand reduce patient recovery times. Typically, endoscopic surgicalstapling devices include a tool assembly and a drive assembly that ismovable in relation to the tool assembly to actuate the tool assembly.The drive assembly includes a knife bar having a cutting blade forcutting tissue. The tool assembly includes anvil and cartridgeassemblies that are coupled to each other by a pivot member and movablein relation to each other between open and clamped positions in responseto movement of the drive assembly. The cartridge assembly includes astaple cartridge that has an actuation sled, pushers, and staples.Typically, the drive assembly is movable from a retracted position to anadvanced position to advance the actuation sled into contact with thepushers and eject the staples from the staple cartridge.

Some stapling devices include a staple cartridge that can be replacedafter each firing of the stapling device to facilitate reuse of thestapling device. In such devices, a knife is typically included on thedrive assembly and is reused. Other stapling devices include a reloadassembly that includes a staple cartridge and a drive assembly that canbe replaced after each firing of the stapling device to facilitate reuseof the stapling device. The use of a reload assembly provides a newcutting blade for each firing of the stapling device to maintain thequality of cutting. However, replacement of the drive assembly aftereach firing of the stapling device is costly.

A continuing need exists for a surgical stapling device that can in acost-effective manner provide a sharpened cutting blade through multiplefirings of the stapling device.

SUMMARY

This disclosure is directed to a surgical stapling device that includesa cartridge assembly having a staple cartridge that is replaceable tofacilitate reuse of the stapling device. The staple cartridge includesan actuation sled assembly having an actuation sled, a knife bar, and aretractor link. The retractor link is secured to the knife bar such thatthe actuation sled assembly is movable through a cartridge body of thestaple cartridge. The retractor link is movable from a non-deformedcondition disengaged from the drive assembly to a deformed conditionengaged with the drive assembly to facilitate retraction of theactuation sled assembly or the knife bar after the stapling device isfired.

Aspects of this disclosure are directed to an actuation sled assemblythat includes an actuation sled, a knife bar, and a retractor link. Theactuation sled includes a central portion and spaced wedge memberspositioned on opposite sides of the central portion. The knife barengaged with or fixedly secured to the central portion of the actuationsled and includes a cutting edge positioned above the actuation sled.The retractor link is formed of a resilient material and has a proximalportion and a distal portion. The distal portion defines a longitudinalaxis. The retractor link has a non-deformed condition and a deformedcondition. In the non-deformed condition, the proximal portion of theretractor link bends outwardly from the longitudinal axis defined by thedistal portion of the retractor link, and in the deformed condition, theproximal portion of the retractor link is substantially aligned with thelongitudinal axis of the distal portion of the retractor link.

In aspects of the disclosure, the proximal portion of the retractor linkincludes an engaging member.

In some aspects of the disclosure, the engaging member includes a bendformed on the proximal portion of the retractor link.

In certain aspects of the disclosure, the engaging member includes aprotrusion formed on the proximal portion of the retractor link.

In aspects of the disclosure, the recess is formed in the working memberof the drive assembly.

In some aspects of the disclosure, the recess is formed in the flexibledrive beam of the drive assembly.

In certain aspects of the disclosure, the retractor link is formed fromspring steel.

In some aspects of the disclosure, the knife bar includes a baseportion, and the central portion of the actuation sled is molded aboutthe base portion of the knife bar to secure the knife bar to theactuation sled.

In certain aspects of the disclosure, the knife bar includes a bodyportion that defines a longitudinally extending recess and the distalportion of the retractor link is secured within the longitudinallyextending recess.

Other aspects of the disclosure are directed to a surgical staplingdevice including a tool assembly and a drive assembly. The tool assemblyincludes an anvil and a cartridge assembly. The cartridge assemblyincludes a staple cartridge having a cartridge body, pushers, staples,and an actuation sled assembly. The cartridge body defines a knife slotand staple receiving pockets positioned on each side of the knife slot.Each of the staple receiving pockets receives one of the staples and oneof the pushers. The actuation sled assembly includes an actuation sled,a knife bar, and a retraction link. The actuation sled includes acentral portion and spaced wedge members positioned on opposite sides ofthe central portion. The central portion is received and movable withinthe knife slot. The knife bar includes a cutting edge that is positionedabove the actuation sled and extends from the knife slot. The retractorlink is formed of a resilient material and has a proximal portion and adistal portion. The distal portion of the retractor link defines alongitudinal axis. The retractor link has a non-deformed condition and adeformed condition. In the non-deformed condition, the proximal portionof the retractor link bends outwardly from the longitudinal axis of thedistal portion of the retractor link and outwardly of the knife slot,and in the deformed condition, the proximal portion of the retractorlink is substantially aligned with the longitudinal axis of the distalportion of the retractor link. The proximal portion of the retractorlink includes an engaging member. The drive assembly includes a flexibledrive beam and a working end that is secured to the flexible drive beam.The drive assembly is movable between retracted and advanced positionsin relation to the tool assembly to eject the staples from the cartridgebody. The drive assembly defines a recess that receives the engagingmember of the retractor link when the retractor link is in the deformedcondition to couple the knife bar of the actuation sled assembly to thedrive assembly.

In aspects of the disclosure, the stapling device includes an adapterassembly having a proximal portion and a distal portion that supportsthe tool assembly.

In some aspects of the disclosure, the stapling device includes a handleassembly that is coupled to the proximal portion of the adapterassembly.

In certain aspects of the disclosure, the cartridge assembly is coupledto the anvil to facilitate movement of the tool assembly betweenunclamped and clamped positions.

In aspects of the disclosure, the drive assembly is movable from theretracted position to a drive assembly clamped position to move the toolassembly from the unclamped position to the clamped position.

In some aspects of the disclosure, the drive assembly is movableindependently of the actuation sled assembly between the retractedposition and the drive assembly clamped position.

Other features of the disclosure will be appreciated from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the disclosed surgical stapling device are describedherein below with reference to the drawings, wherein:

FIG. 1 is a side perspective view of a surgical stapling deviceaccording to aspects of the disclosure with a tool assembly of thestapling device in an open position;

FIG. 2 is an enlarged view of the indicated area of detail of FIG. 1 ;

FIG. 3 is a side perspective view of the tool assembly of the staplingdevice shown in FIG. 1 with a staple cartridge of a cartridge assemblyof the tool assembly separated from a channel of the cartridge assembly;

FIG. 4 is a side perspective exploded view of the staple cartridge ofthe cartridge assembly of the tool assembly shown in FIG. 3 ;

FIG. 5 is an enlarged view of the indicated area of detail shown in FIG.4 illustrating an actuation sled assembly of the staple cartridge shownin FIG. 4 ;

FIG. 6A is a side perspective, exploded view of the actuation sledassembly shown in FIG. 5 ;

FIG. 6B is a perspective view from a proximal end of the actuation sledassembly shown in FIG. 5 ;

FIG. 7 is a cross-sectional view taken along section line 7-7 of FIG.6B;

FIG. 8 is a bottom, perspective view of the staple cartridge of thecartridge assembly shown in FIG. 4 ;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 8;

FIG. 10 is a perspective view of a proximal portion of the staplecartridge shown in FIG. 8 with the actuation sled assembly shown in FIG.8 ;

FIG. 11 is a side view of the tool assembly shown in FIG. 2 with thetool assembly moved to the clamped position and the channel memberremoved;

FIG. 12 is an enlarged view of the indicated area of detail shown inFIG. 11 ;

FIG. 13 is a side perspective view of a drive assembly and the actuationsled assembly of the surgical stapling device shown in FIG. 1 inretracted positions;

FIG. 14 is a cross-sectional view taken along section line 14-14 of FIG.12 ;

FIG. 15 is a side cutaway view of a proximal portion of the toolassembly with the channel of the cartridge assembly removed as the toolassembly is fired;

FIG. 16 is a cross-sectional view taken along section line 16-16 of FIG.15 ;

FIG. 17 is a side cutaway view of the proximal portion of the toolassembly with the channel of the cartridge assembly removed as the driveassembly is returned to its retracted position after the stapling devicehas been fired;

FIG. 18 is a cross-sectional view taken along section line 18-18 of FIG.17 ;

FIG. 19 is a side perspective view from above of the proximal portion ofthe staple cartridge after the staple cartridge has been fired andremoved from the channel of the cartridge assembly;

FIG. 20 is a side perspective view of an alternate version of theactuation sled assembly of the surgical stapling device shown in FIG. 1;

FIG. 21 is a side perspective, exploded view of a knife assembly of theactuation sled assembly shown in FIG. 20 ;

FIG. 22 is a side perspective view of an alternate version of the driveassembly of the surgical stapling device shown in FIG. 1 in theirretracted positions;

FIG. 23 is a side perspective view of an alternate version of theactuation sled assembly of the surgical stapling device shown in FIG. 1;

FIG. 24 is an exploded view of the actuation sled assembly of FIG. 23 ;

FIG. 25 is a cross-sectional view taken along section line 25-25 of FIG.23 ;

FIG. 26 is a cross-sectional view taken through the distal portion ofthe tool assembly with the stapling device in the clamped and firedposition and the drive assembly in the advanced position;

FIG. 27 is a cross-sectional view taken through the distal portion ofthe tool assembly with the stapling device in the clamped and firedposition as the drive assembly moves from the advanced position backtowards the retracted position with the knife bar coupled to the driveassembly; and

FIG. 28 is a cross-sectional view taken through the proximal portion ofthe tool assembly with the stapling device in the clamped and firedposition and the drive assembly in the retracted position with the knifebar uncoupled from the drive assembly.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detailwith reference to the drawings in which like reference numeralsdesignate identical or corresponding elements in each of the severalviews. However, it is to be understood that disclosed aspects of thesurgical stapling device are merely exemplary of the disclosure and maybe embodied in various forms. Well-known functions or constructions arenot described in detail to avoid obscuring the disclosure in unnecessarydetail. Therefore, specific structural and functional details disclosedherein are not to be interpreted as limiting, but merely as a basis forthe claims and as a representative basis for teaching one skilled in theart to variously employ the disclosure in virtually any appropriatelydetailed structure.

In this description, the term “proximal” is used generally to refer tothat portion of the device that is closer to a clinician during use ofthe device in its customary fashion, while the term “distal” is usedgenerally to refer to that portion of the device that is farther fromthe clinician during use of the device in its customary fashion. Inaddition, directional terms such as front, rear, upper, lower, top,bottom, and similar terms are used to assist in understanding thedescription and are not intended to limit the disclosure. Further, theterm “clinician” is used generally to refer to medical personnelincluding doctors, nurses, surgeons, and support personnel.

The disclosure is directed to a surgical stapling device that includes atool assembly having a drive assembly, an anvil, and a cartridgeassembly. The cartridge assembly includes a replaceable staple cartridgethat includes an actuation sled assembly having an actuation sled, aknife bar, and a retractor link. The retractor link is secured to theknife bar such that the actuation sled assembly is movable through acartridge body of the staple cartridge. The retractor link is movablefrom a non-deformed condition disengaged from the drive assembly to adeformed condition engaged with the drive assembly to facilitateretraction of the actuation sled assembly after the stapling device isfired.

FIG. 1 illustrates a surgical stapling device shown generally asstapling device 10 that includes a handle assembly 12, an adapterassembly 14, and a tool assembly 16. The handle assembly 12 is poweredand includes a stationary handgrip 18 and actuation buttons 20. Theactuation buttons 20 are operable to actuate various functions of thetool assembly 16 via the adapter assembly 14, i.e., approximation of thetool assembly 16, and firing of the tool assembly 16. In certain aspectsof the disclosure, the handle assembly 12 includes a motor (not shown)batteries (not shown), and circuitry that couples the batteries to themotor to operate the stapling device 10. Although the stapling device 10is illustrated as a powered stapling device, it is envisioned that theadvantages of this disclosure are suitable for use with manually poweredsurgical stapling devices as well as robotically controlled staplingdevices. U.S. Pat. No. 5,865,361 describes a stapling device thatincludes exemplary aspects of a manually powered stapling device.

The adapter assembly 14 defines a longitudinal axis “X” and includes aproximal portion 14 a and a distal portion 14 b. The proximal portion 14a of the adapter assembly 14 is coupled to the handle assembly 12, andthe distal portion 14 b of the adapter assembly 14 is coupled to thetool assembly 16.

FIGS. 2 and 3 illustrate the tool assembly 16 which includes an anvil 32and a cartridge assembly 34. In aspects of the disclosure, the cartridgeassembly 34 is pivotably supported in relation to the anvil 32 and theadapter assembly 14 such that the tool assembly 16 is movable between anopen position (FIG. 2 ) and a clamped position (FIG. 11 ). Alternately,it is envisioned that the anvil 32 may be pivotably supported inrelation to the cartridge assembly 34 and the adapter assembly 14.

FIGS. 2-5 illustrate the cartridge assembly 34 which includes a channelmember 40 and a staple cartridge 42. The channel member 40 includes sidewalls 44 and a bottom wall 46 that define a cavity 48. The staplecartridge 42 is removably received within the cavity 48 of the channelmember 38 and is replaceable to facilitate reuse of the stapling device10. Each of the side walls 44 defines a recess 49 (FIG. 3 ) on an upperedge of the side wall 44.

FIG. 4 illustrates the staple cartridge 42 which includes a cartridgebody 50 that defines a knife slot 52 and staple receiving pockets 54positioned on each side of the knife slot 52. In aspects of thedisclosure, the knife slot is centrally located along a longitudinalaxis of the cartridge body 50. In aspects of the disclosure, the staplereceiving pockets 54 are aligned in two or more rows on opposite sidesof the knife slot 52. The cartridge body 50 includes laterally extendingprotrusions 56 that are received within the recesses 49 (FIG. 3 ) of thechannel member 40 (FIG. 3 ) to properly position the staple cartridge 40within the cavity 46 of the channel member 38. The cartridge body 50also includes knife guards 58 that are positioned on opposite sides ofthe knife slot 52 at a proximal portion of the cartridge body 50.

The staple cartridge 42 includes staples 60, pushers 62, a staple guard64, and an actuation sled assembly 66. The staples 60 are supported onthe pushers 62 and received within the staple receiving pockets 54 ofthe cartridge body 50. The staple guard 64 is U-shaped and is secured tothe bottom of the cartridge body 50 to retain the staples 60 and pushers62 within the cartridge body 50. In aspects of the disclosure, thestaple guard 64 includes resilient fingers 70 that are received insnap-fit fashion in recesses 72 in the cartridge body 50 to secure aproximal portion of the staple guard 64 to the cartridge body 50. Thestaple guard 64 may also include openings 74 that receive protrusions 75on the cartridge body 50 to retain the staple guard 64 on the cartridgebody 50.

FIGS. 5-12 illustrate the actuation sled assembly 66 which includes anactuation sled 76, a knife bar 78, and a retractor link 80. Theactuation sled assembly 66 is received in the cartridge body 50 of thestaple cartridge 42 and is movable within the cartridge body 50 betweensled retracted and sled advanced positions. The actuation sled 76includes a central portion 82 and spaced wedge members 84 that arepositioned on opposite sides of the central portion 82. The wedgemembers 84 are configured to engage and lift the pushers 62 as theactuation sled assembly 66 is moved from the sled retracted position tothe sled advanced position to eject the staples 60 from staple receivingpockets 54 of the cartridge body 50. The central portion 82 of theactuation sled 76 is received in the knife slot 52 of the cartridge body50 and is movable through the knife slot 52 to limit the actuation sledassembly 66 to linear movement.

The knife bar 78 is fixedly secured to the central portion 82 of theactuation sled 76 and includes a body portion 85, a base portion 86, andknife 88. The body portion 85 of the knife bar 78 is received in andmovable through the knife slot 52. The knife 88 is supported on an uppersurface of the body portion 85 and includes a distally facing cuttingedge 88 a. The cutting edge 88 a extends upwardly from the body portion85 to a position above a tissue engaging surface 50 a of the cartridgebody 50 and is shielded by the knife guards 58 (FIG. 4 ). The knifeguards 58 may be integrally formed with the cartridge body 50 or securedthereto. The base portion 86 extends downwardly from the body portion 85and is secured to the central portion 82 of the actuation sled 76. Inaspects of the disclosure, the base portion 86 defines two openings 90that receive portions of the central portion 82 of the actuation sled76. In certain aspects of the disclosure, the actuation sled 76 isformed of plastic and the knife bar 78 is formed from metal, and theactuation sled 76 is molded about the base portion 86 of the knife bar78.

The retractor link 80 is secured to the body portion 85 of the knife bar78 in cantilevered fashion. In aspects of the disclosure, the retractorlink 80 is formed of a resilient material, e.g., spring steel, andincludes a distal portion 80 a and a proximal portion 80 b. The proximalportion 80 b of the retractor link 80 includes an engaging member whichmay be in the form of an inwardly extending protrusion 94. The distalportion 80 a defines a longitudinal axis and is secured to the centralportion 82 of the knife bar 78, and the proximal portion 80 b extendsproximally from the actuation sled 76. In aspects of the disclosure, thebody portion 85 of the knife bar 78 defines a longitudinally extendingrecess 92 (FIG. 6A), and the distal portion 80 a of the retractor link80 is secured within the recess 92. The retractor link 80 is movablebetween a non-deformed condition and a deformed condition. In thenon-deformed condition, the proximal portion of the retractor link 80bends outwardly from the longitudinal axis defined by the distal portion80 of the retractor link 80 and outwardly of the knife slot 52 of thecartridge body 50. When the actuation sled assembly 66 is advancedthrough the knife slot 52, the proximal portion 80 b of the retractorlink 80 engages an inner wall of the cartridge body 50 defining theknife slot 52 and is moved to the deformed condition in which the distaland proximal portions 80 a, 80 b of the retractor link 80 arelongitudinally aligned. The actuation sled 76 of the actuation sledassembly 66 includes a proximal portion that defines a centrally locatedcutout 96 (FIG. 6B).

The stapling device 10 includes a drive assembly 98 illustrated in FIG.13 which includes a working member 100 and a flexible drive beam 102.The working member 100 of the drive assembly 98 is partly received inthe cutout 96 of the actuation sled 76 when the drive assembly 98 is ina clamped position and the actuation sled assembly 66 is in a retractedposition. The drive assembly 98 is movable from a retracted position,through a drive assembly clamped position, to advanced position andincludes a flexible drive beam 102 that has a proximal portion (notshown) and a distal portion 106 that is secured to the working member100. In aspects of the disclosure, the flexible drive beam 102 is formedfrom stacked laminates. Alternately, other configurations of theflexible drive beam 102 are envisioned. When the drive assembly 98 ismoved from the retracted position to the drive assembly clampedposition, the working member 100 moves independently of the actuationsled assembly 66 to move the tool assembly 16 (FIG. 1 ) from theunclamped position to the clamped position.

The working member 100 of the drive assembly 98 has an I-shapedconfiguration and includes a first beam 108, a second beam 110, and avertical strut 112 that connects the first beam 108 to the second beam110. The vertical strut 112 is aligned with the knife slot 52 (FIG. 16 )in the cartridge body 50 and is positioned to engage the actuation sledassembly 66. When the drive assembly 98 moves from the retractedposition to the clamped position in the direction of arrow “A” in FIG.11 , the first and second beams 108, 110 engage the anvil 32 and thecartridge assembly 34 to pivot the cartridge assembly 34 in thedirection of arrow “B” in FIG. 11 . In the clamped position of the driveassembly 98, the working member 100 of the drive assembly 98 is receivedin the cutout 96 of the actuation sled 76 of the actuation sled assembly66 and is in close approximation or abutting relation to the actuationsled assembly 66. When the drive assembly 98 is moved from the clampedposition towards the advanced position, the vertical strut 112 of theworking member 100 of the drive assembly 98 engages and advances theactuation sled assembly 66 through the knife slot 52 to move theactuation sled assembly 66 between the sled retracted and advancedpositions.

The vertical strut 112 of the working member 100 of the drive assembly98 defines a recess or opening 114. When the actuation sled assembly 66is moved by the drive assembly 98 from the sled retracted positiontowards the sled advanced position, the retractor link 80 of theactuation sled assembly 66 moves with the actuation sled assembly 66into the knife slot 52 of the cartridge body 50. As the proximal portion80 b of the retractor link 80 moves into the knife slot 52 of thecartridge body 50, engagement of the proximal portion 80 b of theretractor link 80 with the cartridge body 50 moves the retractor link 80from the undeformed condition to the deformed condition. When thisoccurs, the protrusion 94 of the retractor link 80 is received in therecess or opening 114 formed in the vertical strut 112 to secure theactuation sled assembly 66 to the working member 100 of the driveassembly 98.

FIGS. 13-15 illustrate the tool assembly 16 with the drive assembly 98in the drive assembly clamped position and the actuation sled assembly66 in the sled retracted position. Although not described in detailherein, the cartridge assembly 34 includes a lockout member 120 thatprevents refiring of the tool assembly 16 with a spent staple cartridge.The lockout member 120 does not form part of this disclosure and willnot be described in further detail herein. When the drive assembly 98 isin the clamped position, and the actuation sled assembly 66 is in thesled retracted position, the retractor link 80 is in its non-deformedcondition in which the proximal portion 80 b of the retractor link 80 isbent outwardly of the knife slot 52 of the cartridge body 50. Toaccommodate the proximal portion 80 b of the retractor link 80 when theretractor link 80 is in the non-deformed condition, the cartridge body50 defines a pocket 122 (FIG. 14 ) that includes a curved wall 122 athat has a curvature that corresponds to the curvature of the proximalportion 80 b of the retractor link 80 in the non-deformed condition.

FIG. 16 illustrates the tool assembly 16 as the drive assembly 98 ismoved from the clamped position towards the advanced position to movethe actuation sled assembly 66 from the sled retracted position (FIG. 14) towards the sled advanced position. When the drive assembly moves inthe direction of arrow “C” from the drive assembly clamped positiontowards the advanced position, the working member 100 of the driveassembly 98 moves the actuation sled assembly 66 in the direction ofarrow “D”. As the proximal portion 80 b of the retractor link 80 movesinto the knife slot 52 of the cartridge body 50, the proximal portion 80b of the retractor link 80 engages the curved wall 122 a of thecartridge body 50 and is moved from the undeformed condition to thedeformed condition in the direction of arrow “E”. As the retractor link80 moves to the deformed condition, the protrusion 94 of the retractorlink 80 is received within the recess 114 formed in the vertical strut112 of the working member 100 to couple the actuation sled assembly 66to the working member 100 of the drive assembly 98. As the drive member98 moves towards the advanced position to move the actuation sledassembly 66 towards the sled advanced position, the spaced wedge members84 (FIG. 13 ) of the actuation sled 76 engage the pushers 62 (FIG. 4 )of the staple cartridge 42 to eject the staples 60 from the staplereceiving slots 54 of the cartridge body 50 into the anvil 32.

FIGS. 17 and 18 illustrate the tool assembly 16 as the drive assembly 98is returned from the advanced position to the retracted position in thedirection of arrow “F”. As described above, the protrusion 94 of theretractor link 80 is received in the recess or opening 114 in thevertical strut 112 of the working member 100 of the drive assembly 98 tocouple the actuation sled assembly 66 to the drive assembly 98. Thus, asthe drive assembly 98 returns from the advanced position to theretracted position, the actuation sled assembly 66 also moves from thesled advanced position to the sled retracted position. When theactuation sled assembly 66 returns to the sled retracted position andthe drive assembly 98 is returned to the drive assembly clampedposition, the proximal portion 80 b of the retractor link 80 becomesaligned with the pocket 122 in the cartridge body 50. When this occurs,the proximal portion 80 b of the retractor link 80 returns to thenon-deformed position in the direction of arrow “G” in FIG. 18 touncouple the actuation sled assembly 66 from the drive assembly 98.After the actuation sled assembly 66 is uncoupled from the driveassembly 98, the drive assembly 98 continues to move towards theretracted position independently of the actuation sled assembly 66. Inthis position, the spent staple cartridge 42 (FIG. 19 ) can be removedfrom channel member 34 (FIG. 3 ) and replaced with a fresh staplecartridge to facilitate reuse of the stapling device 10 (FIG. 1 ).

FIGS. 20-22 illustrate an alternate version of the actuation sledassembly shown generally as actuation sled assembly 266 and the driveassembly shown generally as drive assembly 298 (FIG. 22 ). The actuationsled assembly 266 is like actuation sled assembly 66 (FIG. 6A) andincludes an actuation sled 276, a knife bar 278, and a retractor link280. The knife bar 278 includes a knife 288 having a distally facingcutting edge 288 a. The actuation sled assembly 266 is received in thecartridge body 50 (FIG. 4 ) of the staple cartridge 42 and is movablewithin the cartridge body 50 between sled retracted and sled advancedpositions. The actuation sled 276 includes a central portion 282, andspaced wedge members 284 that are positioned on opposite sides of thecentral portion 282. The wedge members 284 are configured to engage andlift the pushers 62 (FIG. 4 ) as the actuation sled assembly 266 ismoved from the sled retracted position to the sled advanced position toeject the staples 60 (FIG. 4 ) from staple receiving pockets 54 of thecartridge body 50. The central portion 282 of the actuation sled 276 isreceived in the knife slot 52 (FIG. 4 ) of the cartridge body 50 and ismovable through the knife slot 52 to limit the actuation sled assembly266 to linear movement. The actuation sled assembly 266 differs from theactuation sled assembly 66 (FIG. 6A) in that the retractor link 280includes a proximal portion that includes an engaging member in the formof a bend 294.

The drive assembly 298 is like the drive assembly 98 and includes aworking member 300 and a flexible drive beam 302. The working member 300and the flexible drive beam 302 are as described above regarding workingmember 100 and flexible drive beam 102 except that a distal portion ofthe flexible drive beam 302 defines a recess or opening 314. In someaspects of the disclosure, the recess or opening 314 may also be formedin the vertical strut 312 of the working member 300.

The actuation sled assembly 266 and the drive assembly 298 function inthe same manner as the actuation sled assembly 66 and the drive assembly98. More specifically, when the drive assembly 298 moves from the driveassembly clamped position towards the advanced position to move theactuation sled assembly 266 from the sled retracted position towards thesled advanced position, the retractor link 280 moves into the knife slot52 (FIG. 4 ) and is deformed from the undeformed condition to thedeformed condition. When this occurs, the bend 294 is received in theopening 314 defined in the drive assembly 298 to couple the actuationsled assembly 266 to the drive assembly 298.

FIGS. 23 to 28 illustrate an alternate version of the actuation sledassembly and drive assembly of the stapling device 10 (FIG. 1 ) shown asactuation sled assembly 400 and drive assembly 500 (FIG. 27 ). Theactuation sled assembly 400 includes an actuation sled 402, a knife bar404, and a retractor link 406. The actuation sled assembly 400 is likethe actuation sled assemblies 66 (FIG. 5 ) and 266 (FIG. 21 ) exceptthat the knife bar 404 is not secured to the actuation sled 402. Theactuation sled assembly 400 is received in the cartridge body 50 (FIG.27 ) of the staple cartridge 42 (FIG. 4 ) and is movable within thecartridge body 50 between sled retracted and sled advanced positions.The actuation sled 402 includes a central portion 408 and spaced wedgemembers 410 that are positioned on opposite sides of the central portion408. The wedge members 410 are configured to engage and lift the pushers62 (FIG. 4 ) as the actuation sled assembly 400 is moved from the sledretracted position towards the sled advanced position to eject thestaples 60 (FIG. 4 ) from staple receiving pockets 54 (FIG. 4 ) of thecartridge body 50. The central portion 408 of the actuation sled 402 isreceived in the knife slot 52 of the cartridge body 50 and is movablethrough the knife slot 52 to limit the actuation sled assembly 400 tolinear movement. The central portion 408 of the actuation sled 402defines a proximally extending finger 412, a longitudinally extendingrib 414 (FIG. 24 ), and a member 416 that has a flat surface 416 a. Therib 414 has a curved proximal surface 414 a. The actuation sled 402 alsodefines a cutout 420 between the wedge members 410 that is dimensionedto receive the knife bar 404 as described below. The rib 414 and themember 416 are received in the cutout 420 and the flat surface 416 a ofthe member 416 extends proximally of the cutout 420.

The knife bar 404 includes a body portion 422, a base portion 424, andknife 426. The body portion 422 of the knife bar 404 is received in andmovable through the knife slot 52 of the cartridge body 50 (FIG. 4 ).The knife 426 includes a distally facing cutting edge 426 a and issupported on an upper end of the body portion 422 of the knife bar 404and projects proximally of a lower portion of the body portion 422 ofthe knife bar 404. The cutting edge 426 a extends upwardly from the bodyportion 422 of the knife bar 404 to a position above the tissue engagingsurface 50 a (FIG. 4 ) of the cartridge body 50 and is shielded by theknife guards 58 (FIG. 4 ) when the knife bar 404 is in the retractedposition. The base portion 424 is secured to or formed on the lower endof the body portion 422 and defines a channel 428 (FIG. 24 ) that ispositioned to receive the rib 414 of the actuation sled 402. The baseportion 424 extends outwardly of the body portion 422 and is positionedto ride along a bottom wall of the staple guard 64 (FIG. 4 ). Thechannel 428 in the base portion 424 of the knife bar 404 is defined inpart by a curved proximal portion 428 a (FIG. 27 ) that is configured toengage the curved proximal surface 414 a of the rib 414 when the knifebar 404 is engaged with the actuation sled 402. The body portion 422 ofthe knife bar 404 defines a longitudinally extending recess 430 (FIG. 24) that receives a distal portion 406 a of the retractor link 406. Inaspects of the disclosure, the actuation sled 402 is formed of plasticand the knife bar 404 is formed from metal.

The retractor link 406 is secured to the body portion 422 of the knifebar 404 in cantilevered fashion. In aspects of the disclosure, theretractor link 406 is formed of a resilient material, e.g., springsteel, and includes the distal portion 406 a and a proximal portion 406b. The proximal portion 406 b of the retractor link 406 includes anengaging member which may be in the form of a 90-degree bend 434. Thedistal portion 406 a defines a longitudinal axis and is secured to thecentral portion 408 of the knife bar 404 within the recess 430. Inaspects of the disclosure, the distal portion 406 a of the retractorlink 406 has a u-shaped portion 435 that receives the body portion 422of the knife bar 404. The proximal portion 406 b of the retractor link406 extends proximally from the knife bar 404. The retractor link 406 asdescribed above regarding the retractor link 280 (FIG. 20 ) is movablebetween a non-deformed condition and a deformed condition. In thenon-deformed condition, the proximal portion 406 b of the retractor link406 bends outwardly from the longitudinal axis defined by the distalportion 406 a of the retractor link 406 and outwardly of the knife slot52 (FIG. 4 ) of the cartridge body 50. When the actuation sled assembly400 is advanced through the knife slot 52 of the cartridge body 50, theproximal portion 406 b of the retractor link 406 engages an inner wallof the cartridge body 50 defining the knife slot 52 and is moved to thedeformed condition in which the distal and proximal portions 406 a and406 b of the retractor link 406 are longitudinally aligned.

The drive assembly 500 (FIG. 26 ) is like the drive assemblies 98 (FIG.13 ) and 298 (FIG. 22 ) and includes a working member 502 and a flexibledrive beam 504 (FIG. 27 ). The distal portion of the flexible drive beam504 defines a recess or opening 506 (FIG. 27 ) that receives the bend434 in the proximal portion 406 b of the retractor link 406 when theretractor link 406 is deformed. The working member 502 of the driveassembly 500 defines a distally facing pocket 510 (FIG. 27 ) thatreceives the upper portion of the body portion 422 and knife 426 of theknife bar 404 (FIG. 26 ) when the working member 502 is moved intoengagement with the knife bar 404.

The actuation sled assembly 400 and the drive assembly 500 function inthe same manner as the actuation sled assembly 266 and the driveassembly 298 described above except that the actuation sled 402 is onlyin abutting relation to the knife bar 404 and does not return to theretracted position with the knife bar 404 as the knife bar 404 is movedfrom the advanced position to the retracted position with the driveassembly 500. More specifically, when the drive assembly 500 moves fromthe drive assembly clamped position towards the drive assembly advancedposition to move the actuation sled assembly 400 from the sled retractedposition towards the sled advanced position, the retractor link 406moves into the knife slot 52 (FIG. 4 ) and is deformed from theundeformed condition to the deformed condition. When this occurs, thebend 434 of the retractor link 406 is received in the opening 506 of thedrive assembly 500 to couple the drive assembly 500 with the knife bar404. As the drive assembly 500 moves towards the advanced position inthe direction of arrow “H” in FIG. 26 , the working member 502 of thedrive assembly 500 engages the actuation sled 402 to move the actuationsled 402 from the sled retracted position to the sled advanced positionto eject staples 60 (FIG. 4 ) from the staple cartridge 42. It is notedthat when the working member 502 of the drive assembly 500 is engagedwith the knife bar 404, the knife 426 of the knife bar 404 is receivedwithin the pocket 510 defined in the working end 502 of the driveassembly 500. In addition, when the knife bar 404 is engaged with theactuation sled 402, the base portion 424 of the knife bar 404 isreceived in the cutout 420 defined by the actuation sled 402. When thebase portion 424 (FIG. 24 ) of the knife bar 404 is received in thecutout 420 (FIG. 25 ) of the actuation sled 402, the base portion 424 issupported on the flat surface 416 a of the member 416 such that the rib414 of the actuation sled 402 is received within the channel 428 definedin the base portion 424 of the knife bar 404.

FIG. 27 illustrates the distal portion of the tool assembly 16 (FIG. 1 )as the drive assembly 500 is moved in the direction of arrow “I” fromthe advanced position back towards the retracted position. As the driveassembly 500 is retracted, the knife bar 404 which is coupled to thedrive assembly 500 by the retractor link 406 also moves towards theretracted position. However, the actuation sled 402 which is only inabutting relation to the knife bar 404 disengages from the knife bar 404and remains in the distal portion of the staple cartridge 42. (FIG. 27).

FIG. 28 illustrates the proximal portion of the tool assembly 16 as thedrive assembly 500 approaches the retracted position. When the driveassembly 500 nears the retracted position, the proximal portion 406 b ofthe retractor link 406 becomes aligned with the pocket 122 in thecartridge body 50 of the staple cartridge 42 and returns to thenon-deformed condition in the direction of arrow “J” to disengage theknife bar 404 from the drive assembly 500. When this occurs, the driveassembly 500 continues to move to the retracted position independentlyof the knife bar 404. Disengaging the knife bar 404 from the driveassembly 500 allows for removal and replacement of the staple cartridge42 to facilitate reuse of the stapling device 10 (FIG. 1 ).

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary aspects of the disclosure. It isenvisioned that the elements and features illustrated or described inconnection with one exemplary embodiment may be combined with theelements and features of another without departing from the scope of thedisclosure. As well, one skilled in the art will appreciate furtherfeatures and advantages of the disclosure based on the above-describedaspects of the disclosure. Accordingly, the disclosure is not to belimited by what has been particularly shown and described, except asindicated by the appended claims.

What is claimed is:
 1. An actuation sled assembly comprising: anactuation sled including a central portion, and spaced wedge memberspositioned on opposite sides of the central portion; a knife bar engagedwith the central portion of the actuation sled, the knife bar includinga cutting edge positioned above the actuation sled; and a retractor linkformed of a resilient material and having a proximal portion and adistal portion, the distal portion defining a longitudinal axis, theretractor link having a non-deformed condition and a deformed condition,wherein in the non-deformed condition, the proximal portion of theretractor link bends outwardly from the longitudinal axis of the distalportion of the retractor link and in the deformed condition, theproximal portion of the retractor link is substantially aligned with thelongitudinal axis of the distal portion of the retractor link.
 2. Theactuation sled assembly of claim 1, wherein the proximal portion of theretractor link includes an engaging member.
 3. The actuation sledassembly of claim 2, wherein the engaging member includes a bend formedon the proximal portion of the retractor link.
 4. The actuation sledassembly of claim 2, wherein the engaging member includes a protrusionformed on the proximal portion of the retractor link.
 5. The actuationsled assembly of claim 2, wherein the retractor link is formed fromspring steel.
 6. The actuation sled assembly of claim 2, wherein theknife bar includes a base portion, and the central portion of theactuation sled is molded about the base portion of the knife bar tofixedly secure the knife bar to the actuation sled.
 7. The actuationsled assembly of claim 2, wherein the knife bar includes a body portionthat defines a longitudinally extending recess and the distal portion ofthe retractor link is secured within the longitudinally extendingrecess.
 8. A surgical stapling device comprising: a tool assemblyincluding: an anvil; a cartridge assembly including a staple cartridgehaving a cartridge body, pushers, staples, and an actuation sledassembly, the cartridge body defining a knife slot and staple receivingpockets positioned on each side of the knife slot, each of the staplereceiving pockets receiving one of the staples and one of the pushers,the actuation sled assembly including: an actuation sled including acentral portion and spaced wedge members positioned on opposite sides ofthe central portion, the central portion received and movable within theknife slot; a knife bar engaged with the central portion of theactuation sled, the knife bar including a cutting edge positioned abovethe actuation sled and extending from the knife slot; and a retractorlink formed of a resilient material and having a proximal portion and adistal portion, the distal portion of the retractor link defining alongitudinal axis, the retractor link having a non-deformed conditionand a deformed condition, wherein in the non-deformed condition, theproximal portion of the retractor link bends outwardly from thelongitudinal axis of the distal portion of the retractor link andoutwardly of the knife slot, and in the deformed condition, the proximalportion of the retractor link is substantially aligned with thelongitudinal axis of the distal portion of the retractor link, theproximal portion of the retractor link including an engaging member; anda drive assembly including a flexible drive beam and a working endsecured to the flexible drive beam, the drive assembly being movablebetween retracted and advanced positions in relation to the toolassembly to eject the staples from the cartridge body, the driveassembly defining a recess that receives the engaging member of theretractor link when the retractor link is in the deformed condition tocouple the knife bar of the actuation sled assembly to the driveassembly.
 9. The surgical stapling device of claim 8, wherein the recessis formed in the working member of the drive assembly.
 10. The surgicalstapling device of claim 9, wherein the engaging member includes aprotrusion on the proximal portion of the retractor link.
 11. Thesurgical stapling device of claim 8, wherein the recess is formed in theflexible drive beam of the drive assembly.
 12. The surgical staplingdevice of claim 11, wherein the engaging member includes a bend on theproximal portion of the retractor link.
 13. The surgical stapling deviceof claim 8, wherein the retractor link is formed from spring steel. 14.The surgical stapling device of claim 8, wherein the knife bar includesa base portion, and the central portion of the actuation sled is moldedabout the base portion of the knife bar to fixedly secure the knife barto the actuation sled.
 15. The surgical stapling device of claim 8,wherein the knife bar includes a body portion that defines alongitudinally extending recess and the distal portion of the retractorlink is secured within the longitudinally extending recess.
 16. Thesurgical stapling device of claim 8, further including an adapterassembly having a proximal portion and a distal portion, the distalportion of the adapter assembly supporting the tool assembly.
 17. Thesurgical stapling device of claim 8, further including a handle assemblycoupled to the proximal portion of the adapter assembly.
 18. Thesurgical stapling device of claim 8, wherein the cartridge assembly iscoupled to the anvil to facilitate movement of the tool assembly betweenunclamped and clamped positions.
 19. The surgical stapling device ofclaim 18, wherein the drive assembly is movable from the retractedposition to a drive assembly clamped position to move the tool assemblyfrom the unclamped position to the clamped position.
 20. The surgicalstapling device of claim 19, wherein the drive assembly is movableindependently of the actuation sled assembly between the retractedposition and the drive assembly clamped position.